Cellulose digester



Jan. 9, 1934. I F, KRUGER cELLULosE DIGESTER yFiled Nov. 5, 1931 I45lining.

Patented l Jan. 9, 1934 1,943,221 CELL'ULOSE DIGESTEB Fritz Krger,Mannheim-Waldhof,

' signor to Zellstoffabrlk Waldho Waldhof, Germany Applioatio v and in l2 Claims.

Up to now in cellulose digesters provided with pump operated circulationthe portion of the circulating conduit situated within the digester hasbeen constructed in various ways. For ex- 5 ample the said conduithasbeen led up to only the inner surface of the digester wall and coveredwith a sieve member or it was allowed to open into annular channelswhich likewise were cov-` members. Sometimes the ends` ered with sieveof the pipe were also led to the middle of the digester and wereprovided with fine apertures on the surface o1' their casing throughwhich the lye was sucked or ejected. Covering with sieves is abothersome and very expensive ar- 16 rangement; furthermore it also hasthe disadvantage that should any disturbances arise the orifices of thetube are dimcult to access and that in the course of timefleakagesreadily form at the edges of the sieve plate members. More- 20 over, theannular channels arranged in the lin- Y ing of the digester and formedby the bricks of the lining are only slightly resistant and in the caseof the unavoidable loosening of the structure of the wall, the saidannular channels easily become deteriorated through chemical andmechanical influences. The introduction of the said conduits into themiddle of the digester, either as a straight pipe end or as a worm andso forth, has the great disadvantage that the portion of the interior ofthe digester adjacent to the conduit is rendered diilicult to access andany repairs that may be necessary are made very diflicult, and inaddition when the digester is emptied the portion of the circulatingconduit projecting into the interior of the same forms a disadvantageousobstacle.

These disadvantages are avoided by the new device in that the within thedigester' consists of a circular con- 40 duit provided with ne openingswhich is situated in the proximity of the wall of the digester or isarranged even in the lining of the digester in such a Way that sectionof the conduit projects beyond the said '111e accompanying drawing showsin cross section a device by way of example.

Figure 1 shows a sectional elevation of the lower part oi' the digesterprovided with the device according to the invention, whilst Figure 2shows on a larger scale a cross section of a portion of the lining ofthe digester with the circular conduit embedded there The portion of theconduit situated within the portion of the conduit lying only a portionof the cross' Germany, al:

n November 5, 1931, Serial No. 573,281,

Germany December 30, 1930 (c1.- az-'n interior of the digester,connected by means of the members a a' to the exterior pipe, consists ofthe circular conduit c connected with the members a a through the supplypipes b b', the greater part of the cross section of the said 80circular conduit c being embedded in the lining d d of the digester, asis apparent from Figurel 2 which is drawn on an enlarged scale. Thecircular conduit c is provided at the free part with ne openings e e'through which the lye 65 is sucked or ejected.

The deviceconstructed inthe said manner is naturally applicableindependently of the construction and arrangement of the other parts ofthe forced circulation arrangement. -For example the pumps producingcirculation of the lye may be arranged outside the digester or withinthe casing thereof, or a special lye heater may be inserted in thecirculation conduit, for

example, andy so forth.

What I claim is:

1. A cellulose digester having uid conduits for the pump-operatedcirculation of the digesting lye, the parts of the fluid conduits lyingwithin the digester consisting essentially of an 80 annular pipe ofcircular cross-section, perforated on one side to provide sieve-likeapertures and a short supply pipe therefor arranged close to the wall ofthe digester whereby fluid will be squirted in divergent jets into thedigester. 85

2. A cellulose digester havinguid conduits for the pump-operatedcirculation of the digesting lye, the parts of the fluid conduits lyingwithin the digester consisting essentially of an annular pipe ofcircular cross-section, perforated on one side to provide sieve-likeapertures and a short supply pipe arranged in the wall of the digesterso that only a sieve-like perforated portion of the surface of theconduit projects into the interior vof the digester whereby fluid willbe squirted in divergent ,iets from the conduit into the digester.

rarrz KRGER.

according to the present invention,

Alos

